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Synthesis and characterization of crystalline poly(ethyleneimine)s with mesogenic side chains forming liquid crystals on quaternization
Author(s) -
Masson Patrick,
Heinrich Benoit,
Frègre Yves,
Gramain Philippe
Publication year - 1994
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1994.021950408
Subject(s) - mesogen , polymer chemistry , side chain , thermotropic crystal , bromide , differential scanning calorimetry , polymer , chemistry , copolymer , alkylation , ethyleneimine , ammonium bromide , organic chemistry , liquid crystalline , catalysis , pulmonary surfactant , biochemistry , physics , thermodynamics
The synthesis and thermal properties of a new type of side‐chain liquid‐crystalline polysalts are described. The polymers are first obtained by partial or complete alkylation of a linear poly(ethyleneimine) with 6‐(4‐methoxy‐4′‐biphenylyloxy)hexyl bromide or 12‐(4‐methoxy‐4′‐biphenylyloxy)dodecyl bromide. In a second step, polysalts are prepared by partial or complete quaternization with acyl bromide or dimethyl sulfate. Differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction experiments show that the polymers and copolymers alkylated with the mesogenic groups are all crystalline. When quaternized, they exhibit thermotropic smectic A phases. This behaviour confirms the smectogenic function of the ammonium units located in the backbone, as already observed with poly(4‐vinylpyridinium) salts.